Benjamin t



Nrrhn l States PATENT OFFICE.

BENJAMIN T. BABBITT, for NnWYonK, N. Y.

Speciticntion forming part of Letters Patent No'. SQA 32, dated February 2K5, 18624.

'To all whom/,it may concern: I

Be it known that l, BENJAMIN T. BABBITT,

of the city, county, and lState of New York,

sage round the bore.

Similar letters of reference indicate corresponding parts in both figures.

This invention consists in the construction of apiece of ordnance with a passage Winding spirally round the bore and Within the walls thereof" to serve for a circulation of water or air for the purpose ofkeeping the piece cool when in use, and ior the purpose of cooling the casting in-the manufacture ofthe piece. To enable others skilled in the art to make and use my invention, I will proceed to `describe its construction and operation.

A A are the walls ofthe gun. C is the bore7 andBis a coil of small pipe,o f and Within which the spiral passage a is formed, said passage extending from the breech to near the muzzle .of the Agun and being open at each end, as

shown in Fig. l. 7.*

In a cast-iron gun the coil should be composed of Wrought-dion; but in a brass or bronze gun it may be of wronghtiron. or copper. It isformed by winding a pipe upon a mandrel .of.a'diameter somewhat greater than the intended caliber of the gun, and on the mold in vyhichthe gun is to be cast having been prepared, it is inserted therein in a concentric position. The metal of which the gun is cast shrinking round the coil causes the latter to be .embedded Within it as closely as though it -Were a portion of the casting. Water or air might be allowed to circulate through the coil during the casting process, to cool the metal from near. the center of the casting.

' IVhen the gun is in use, a circulation oi Water through the spiral passa-ge a within the y coil C to keep it cool 4may be obtained by means of a natural flow from an elevated reservoir or by means of apump. Air might be used instead of Water, its circulation throgh the passage being produced by apump or blower, or by means of a portion of the gas evolved at each discharge being permitted to escape in the form of a jet into the outlet of the coil, and so producing a partial vacuum and a draft through the coil; or a circulation of `water through the passage might be induced by this,

last-mentioned means.

The ends of the coil may be so arranged as to have their inlet andyoutlet at the trunnions of the gun,which might in some degree facilip tate the Working of the gun in the use of Water for cooling; but I believe that the necessary facilities may be obtained by making a connection of flexible pipe at one orfboth ends of the coil. v l

What I claim as my invention, and desire to secure by Letters Patent, is-.

The construction of a piece of ordnance with a passage, a, winding vspirally round the bore and wit-hin the walls thereof, substantially as and for the purposes herein specied.-

In. rr. BABBITT.

Witnesses: RICHARDSON GAWLEY,

J. W. CooMBs 

